# System Informatics, 2016, # 7

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An approach to analyze the compatibility of real-time multi-task applications with various combinations of scheduling modes and protocols of access to shared resources when run on multi-core platforms. The approach is based on the recently introduced notion of application density derived from estimation of application feasibility for various values of the processor performance. The software architecture of a relatively simple simulation tool for estimation of the task response time (and therefore, application feasibility) is described, which provides more exact data compared to the known analytical methods when they are applicable. Results of running this tool on a number of benchmarks, including balanced Liu-Layland configurations, are presented along with their analysis and interpretation. The suggested approach allows to indentify an optimal combination of the scheduling mode and access protocol for the given application structure.

This article presents a method for the analysis and verification of Use Case Maps (UCM) models with scenario control structures – protected components and failure handling constructs. UCM models are analyzed and verified with the help of coloured Petri nets (CPN) and the SPIN model checker. An algorithm for translating UCM scenario control structures into CPN is described. The presented algorithm and the verification process are illustrated by the case study of a network protocol.

Extended Finite State Machines (EFSMs) are widely used when deriving tests for checking whether a software implementation meets functional requirements. These tests usually are derived keeping in mind appropriate test purposes such as covering paths, variables, etc. of the specification EFSM. However, it is well known that such tests do not detect many functional faults in an EFSM implementation. In this paper, we propose an approach for increasing the fault coverage of test suites initially derived against the specification EFSM. For this reason, the behavior of the specification EFSM is implemented in Java using a template that is very close to the EFSM description. At the next step, the fault coverage of an initial test suite derived against the specification EFSM is calculated with respect to faults generated by µJava tool. Since the EFSM software implementation is template based, each undetected fault can be easily mapped into a mutant EFSM of the specification machine. Thus, a distinguishing sequence can be derived not for two programs that is very complex but for two machines and there are efficient methods for deriving such a distinguishing sequence for Finite State Machine (FSM) abstractions of EFSMs. As an FSM abstraction, an l-equivalent of an EFSM can be considered that in fact, is a subtree of the successor tree of height l that describes the EFSM behavior under input sequences of length up to l. Such l-equivalents are classical FSMs and if l is not large then a distinguishing sequence can be derived simply enough. The initial test suite augmented with such distinguishing sequences detects much more functional faults in software implementations of a system described by the specification EFSM.

Finite state transducers over semigroups can be regarded as a formal model of sequential reactive programs. In some cases verification of such programs can be reduced to minimization and equivalence checking problems for this model of computation. To solve efficiently these problems certain requirements are imposed on a semigroup these transducers operate on. Minimization of a transducer over a semigroup is performed in three stages: at first the greatest common left-divisors are computed for all states of a transducer, next a transducer is brought to a reduced form by pulling all such divisors ''upstream'', and finally a minimization algorithm for finite state automata is applied to the reduced transducer. As a byproduct of this minimization technique we obtain an equivalence checking procedure for transducers operating on certain classes of semigroups.

This paper presents three approaches to solve the problem of improving sentiment classification for dynamically updating text collections. The paper describes three methods essentially differing from each other. In this case the supervised machine learning and unsupervised machine learning were applied for sentiment classification. The results of methods along with cases, which method is most applicable are shown in the paper. All the experiments were set and the results were obtained on sufficiently representative text collections.

A closed information system is an information system such that its environment does not change it, and there is an information transfer from it to its environment and from its environment to it. In this paper two formalisms (information query systems and conceptual configuration systems) for abstract unified modelling of the artifacts (concept sketches and
models) of the conceptual design of closed information systems, early phase of information systems design process, are proposed. Information query systems defines the abstract unified information model for the artifacts, based on such general concepts as state, information query and answer. Conceptual configuration systems are a formalism for conceptual modelling of information query systems. They defines the abstract unified conceptual model for the artifacts. The basic definitions of the theory of conceptual configuration systems are given. These systems were demonstrated to allow to model both typical and new kinds of ontological elements. The classification of ontological elements based on such systems is described. A language of conceptual configuration systems is defined.